And some Klansmen apparently have branched out into paramilitary type activities. Nine of 10 mercenaries arrested at Slidell, La., in April and accussed of plotting to overthrow the government of Dominica, in the Caribbean, have been connected with the Klan or with Nazi movements, according to the Klanwatch of the Southern Poverty Law Center (SPLC) in Atlanta.

Klan factions are working closer with Nazi groups and becoming more anti-Semetic, says Morris Dees, chief trial attorney for the SPLC.

Stuart Lewengrub of the Jewish Anti-Defamation League of B'nai B'rith in Atlanta notes another KKK trend: "There's a growing tendency of Klan groups splintering off because some members feel they are not violent enough."

Agents of the federal Bureau of Alcohol, Tobacco, and Firearms (ATF) arrested 10 persons last month said to be affiliated with the KKK. They were charged with consiring to bomb an office of the National Association for the Advancement of Colored People (NAACP) in Catonsville, Md.

Also in May, the bureau arrested six people, reported to be members of a KKK splinter group, on charges of conspiring to bomb a Jewish synagogue and Jewish businesses in Nashville, Tenn.

Agents of the firearms bureau also were responsible for the arrests of the would-be mercenaries allegedly heading for Dominica. Several people have pleaded guilty to charges in that case.

The Klan as a whole has not been "targeted" for investigation, says ATF director G. R. Dickerson. But when agents have grounds for "reasonable suspicion" of illegal activities, they can infiltrate a Klan (or other) group and have done so to prevent violence, he says.

* The SPLC Klanwatch project filed suit in US District Court in Texas and won a temporary restraning order against Klan initimidation of Vietnamese refugees who have become shrimpers in a Gulf Coast town. The SPLC also is trying to prove that the operation by the Texas Klan of a paramilitary camp violates an old state law.

The Anti-Defamation League is encouraging states to pass anti-paramilitary training laws. Mr. Dees of the SPLC says 34 states already have such laws but most either do not realize they exist or neglect to use them.

Various Klan groups have operated paramilitary camps in Texas and alabama, and there have been reports of such camps, small in scale, in a few other states.

The SPLC is also suing an Alabama Klan group, alleging violations of civil rights of blacks in a demonstration in that state last year.

Senate and House subcommittees are studying violence in the US, but neither panel has examined KKK activities. A staff official of the House panel described the problem of Klan violence as primarily a state and local issue.

The Anti-Defamation League estimates national membership in various Klan factions at between 9,500 and 11,400, a slight increase over its estimate of about three years ago.

Splinter groups have been "popping up" in a number of states, says Irwin Suall, the ADL's fact-finding director. The groups vie with each other to commit the most "outrageous" acts as they compete for attention and membership, he says.